In sheet handlers, including document handlers, there often exists a need to transport sheets across an unsupported distance or an area where the beam strength of the sheets transported may be problematic (e.g., resulting in jams, wrinkling of the sheet, and the like). In such instances it is well known to employ a corrugation roll or other known apparatus for permitting the desired operation. A corrugation roll is essence is an arrangement of rollers where, generally, a roller (rollers are) is supported along and rotated about one axis and opposed rollers are disposed along another axis to form a nip which, as a sheet passes therebetween, tends to corrugate the sheet.
Devices of this type and sheet handling systems employing them have proven to be generally effective and efficient. However, in certain applications sheet handlers employing corrugating rollers have some short comings. This is particularly true in cases where the corrugating rolls must be disposed adjacent or proximate a bend or curved section of a sheet path. In these cases, sheets in the path are not as adequately controlled as in straight sheet paths. Further, the nip of a corrugating roller set is not as well defined as a set of opposed rollers. Thus, sheets directed toward a corrugating nip can in some cases reach the nip above the desired entrance which generally results in an audible noise or clack, which is undesirable. In other cases, where the sheet directed toward the nip is low, the sheet can fail to be transported therethrough. In either case, too high or to low, the transported sheets can jam and/or otherwise be damaged (e.g., wrinkled), which is, of course, undesirable. It will be understood by those skilled in the art that reaching the nip high, so long as not too high, is generally more desirable as the upper rolls tend to direct the sheet into the nip, although the clack noise, previously noted, is still a problem which is generally annoying to those using the device, as well as those near the device.
The following patents may be relevant to the present invention:
U.S. Pat. No. 5,153,663 Patentee: Bober et al. Issued: Oct. 6, 1992 PA1 U.S. Pat. No. 4,884,794 Patentee: Dinatale et al. Issued: Dec. 5, 1989 PA1 Xerox Disclosure Journal Vol. 8, No. 3, pp. 191-192 Author: Terrence E. Williams Entitle: O RING DOCUMENT CORRUGATOR Dated: May/June 1983
The discharges of these patents may be briefly summarized as follows:
U.S. Pat. No. 5,153,663 discloses a printing apparatus employing compliant sheet corrugating device. The corrugating device disclosed includes a compliant roll that is effective with low weight paper so that such paper is corrugated as it passes through the corrugation nip. The roll, due to its compliant nature, does not, however, corrugate paper having a high beam strength.
U.S. Pat. No. 4,884,794 discloses a reciprocating, recirculating document handler for feeding documents to an image processing station to record the information on the document. The handler includes a belt, which is operable in two directions and which is urged into position by backup rollers. The belt is provided for transporting the documents onto and off of a platen. Apparatus is also provided for inverting the transported documents so that the information on both sides of the document may be recorded and for permitting recirculation of the documents in a simplex and duplex manner.
Xerox Disclosure Journal, Vol. 8, No. 3, pp. 191-192, discloses an "O" ring document corrugating device employing three or more sets of pulleys which are provided to entrain an "O". The sets are arranged with at least two in one plane and a third set in another plane so that the "O" rings entrained thereon form a gradually converging and then interdigitated arrangement. Sheets are acquired along the converging portion and then pass through the interdigitated portion for corrugation.
In accordance with one aspect of the present invention, there is provided sheet handling apparatus for transporting sheets along a path, comprising means for corrugating sheets, and means for receiving a sheet transported along the path, the receiving means responsive to receiving a sheet transported along the path, cooperating with the corrugating means to form a corrugating nip for corrugating the sheet. The receiving means of this aspect of the invention may comprise one or more of the following elements a plurality of spaced belts adapted to engage the sheet being transported along the path to guide the sheet toward the corrugating nip and means responsive to the sheet engaging said belt, for pivoting the belts from a sheet receiving position to a sheet corrugating position. The corrugating means of this aspect of the invention may comprise a plurality of spaced rolls interdigitated with the belts in the sheet corrugating position to form the corrugating nip. Means for driving the rolls to urge the sheet through the corrugation nip can also be included in this aspect of the invention.
In accordance with another aspect of the present invention there is provided a corrugating roller assembly for use in sheet transports in which sheets are transported along a path, which comprises a belt assembly, a plurality of spaced rolls supported rotatably adjacent the belt assembly, and means for urging the belt assembly from a first position, for receiving the sheet being transported along the path to a second position wherein the belt assembly engages the plurality of spaced rolls to form a corrugating nip for corrugating the sheet. The belt assembly of this aspect of the invention may comprise a plurality of spaced pivotably supported belts mounted on the support so that the leading edge of sheet moving along the path engages the plurality of belts to pivot the support so as to move the plurality of belts from the first position to the second position. This aspect also includes interdigitating the plurality of rollers between the plurality of belts to form the corrugation nip.
According to yet another aspect of the present invention, a method for corrugating sheets is provided. The method comprises the steps of: positioning a belt in a first position for engaging a sheet; transporting a sheet into engagement with the belt; moving the belt from the first position to a second position in response to engagement of a sheet with the belt; forming a corrugation nip between the belt in the second position and rolls supported adjacent the belt; and urging the sheet through the corrugation nip. The moving step of the present invention according to this method can further include pivoting the belt in response to the sheet engaging the belt to move the belt from the first position to the second position wherein the pivoting step includes guiding the sheet into the corrugation nip. The urging step of this aspect can include driving the rolls to urge the sheet through the corrugation nip.